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1.
Abstract: The palaeohistological study of the calcified internal organ of Axelrodichthys araripensis Maisey, 1986, a coelacanthiform from the Lower Cretaceous of Brazil (Crato (Aptian) and Santana (Albian) formations of the Araripe Basin), shows that the walls of this organ consist of osseous blades of variable thickness separated from each other by the matrix. This indicates that, in the living individuals, the walls were reinforced by ossified plates, probably separated by conjunctive tissue. This calcified sheath present in Axelrodichthys, as well as in other fossil coelacanths, lies in ventral position relative to the gut and its single anterior opening is located under the opercle, suggesting a direct connection with the pharynx or the oesophagus. The calcified organ of Axelrodichthys, like that of other fossil coelacanths, is here regarded as an ‘ossified lung’ and compared with the ‘fatty lung’ of the extant coelacanth Latimeria. The reinforcement of the pulmonary walls by the overlying osseous blades could be interpreted as a means of adapting volumetric changes in the manner of bellows, a necessary function for ventilation in pulmonary respiration. Other functional hypotheses such as hydrostatic and/or acoustic functions are also discussed.  相似文献   

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The monotypic genus Evanos (Coleoptera: Rutelidae: Geniatini) is revised and a new species, E. danieleae Grossi, n. sp., is described based on specimens collected from Minas Gerais, Brazil. A lectotype is designated for Evanos villatus. Diagnostic characters and comments about the taxonomic status of the genus are given, as well as a key for both species and a distribution map with the known locality records.  相似文献   

4.
Introduction. During a field excursion in Guizhou Province, China, we collected some interesting moss specimens with branch leaves subulate in the upper part, partially and variably bistratose laminae, and a Macromitrium-like epiphytic growth habit on tree trunks. We present morphological and phylogenetic arguments for recognising these plants as a new moss species in the genus Macromitrium Brid. (Orthotrichaceae).

Methods. We compared the morphology of the potential new species with closely related species of Macromitrium, and constructed a phylogenetic tree based on ITS2, trnL and trnG including sampling from 14 other morphologically similar species of Macromitrium.

Key results. The proposed new species belongs to the genus Macromitrium (Orthotrichaceae, Musci). It is closely related to M. gymnostomum Sull. & Lesq. in the phylogenetic tree and according to gametophytic morphological features, represents a hitherto undescribed species.

Conclusions. A new moss species, Macromitrium maolanense Zeyou Zhang, D.D.Li, Jing Yu & S.L.Guo, is described and illustrated. The new species can be distinguished from all congeners by the combination of the following features of the branch leaves: (1) oblong-lanceolate, lanceolate to linear-lanceolate, gradually narrowed to an easily broken subula; (2) rather obscure upper and medial cells, often with blackish stains among cells, densely pluripapillose; (3) variably and partially bistratose laminae in the upper 1/3 portion; (4) basal cells clear, hyaline and smooth, those near costae forming a ‘cancellina region’; and (5) with numerous brownish, clavate gemmae on upper portion. We also discuss the principal distinctive characters separating the new species from its nearest congeners.  相似文献   

5.
Abstract

The genus Coleura contains two species: C. seychellensis restricted to the Seychelles Archipelago and C. afra broadly distributed on the African continent and the Arabian Peninsula. We recently captured and collected specimens of Coleura from Madagascar, an island from which it was previously unknown. Using museum specimens and the new material from Madagascar, we review morphological variation in members of this genus and present characters for species identification. On the basis of these comparisons, specimens from Madagascar are referable to C. afra. We present information on the natural history of the recently discovered Malagasy population.  相似文献   

6.
Three new species of Haplotaxidae collected by Dr. A. Villiers in a cave near Kindia, Guinea, are described. One species belongs to the genus Metataxis Righi, 1985 (M. carnivorus sp. nov.) which is distributed in Western Africa and Eastern America. Another new species is similar to Lycodrilus kraepelini Michaelsen, 1914 incertae sedis: a new genus Villiersia is proposed for both species (V. guanivora sp. nov., V. kraepelini nov. comb.).A third species, of which only immature specimens are available, is tentatively attributed to the genus Haplotaxis: it is remarkable because of its peculiar setae and commissural vessels (H. villiersi sp. nov.).The three species appear to feed on bat guano and, occasionally, on aquatic arthropods. Metataxis, Tiguassu and Villiersia belong to the section of Haplotaxidae endowed with paired sperm sacs and ovisacs.The relations of Haplotaxidae with other families are discussed and it is suggested that the passage from the haplotaxid condition to that of sparganophilids and more advanced lumbriciforms is connected to a change of reproductive strategy and to an enhanced metabolism.  相似文献   

7.
Species discrimination within the gigartinalean red algal genus Hypnea has been controversial. To help resolve the controversy and explore phylogeny within the genus, we determined rbcL sequences from 30 specimens of 23 species within the genus, cox1 from 22 specimens of 10 species, and psaA from 16 species. We describe H. caespitosa as a new species characterized by a relatively slender main axis; a pulvinate growth habit with entangled, anastomosing, and subulate uppermost branches; and unilaterally borne tetrasporangial sori. The new species occurs in the warm waters of Malaysia, the Philippines, and Singapore. The phylogenetic trees of rbcL, psaA, and cox1 sequences showed a distant relationship of H. caespitosa to H. pannosa J. Agardh from Baja California and the marked differentiation from other similar species. The rbcL + psaA tree supported monophyly of the genus with high bootstrap values and posterior probabilities. The analysis revealed three clades within the genus, corresponding to three sections, namely, Virgatae, Spinuligerae, and Pulvinatae first recognized by J. G. Agardh. Exceptions were H. japonica T. Tanaka in Pulvinatae and H. spinella (C. Agardh) Kütz. in Spinuligerae.  相似文献   

8.
ABSTRACT

Background: Woody bamboos of the genus Chusquea grow along a broad range of elevations in the Venezuelan Andes. Their growth-form and density vary along the cloud forest – páramo gradient. In this article, we related ecophysiological traits and population genetic diversity information to explain the distribution of growth-form patterns of Chusquea in the Merida Andes, Venezuela.

Aims: We quantified differences in the ecophysiological response and genetic diversity of scandent cloud forest and shrub-like páramo bamboos of the genus Chusquea, taking in account the differences in their flowering patterns, growth-form and habitat.

Methods: We related low temperature resistance, water relations and leaf gas exchange variables to the growth-form, habitat, flowering patterns and genetic diversity in species of Chusquea. The genetic diversity study was based on Inter Sequence Simple Repeats and Random Amplified Polymorphic DNA markers analysis of cloud forest and páramo populations.

Results: Scandent cloud forest and shrub-like páramo species of Chusquea had a very similar ecophysiological response for all the variables analysed during wet and dry seasons and were capable of enduring freezing temperatures through moderate supercooling. Species associated with the cloud forest – páramo gradient maintained low stomatal conductance and transpiration rates that favoured high leaf water potentials, without limiting photosynthetic rates. Shrub-like bamboos growing above the continuous forest line had a small decline in net photosynthesis rates, associated with an increase in water use efficiency. Both scandent and shrub-like bamboos had a remarkably high genetic diversity, comparable to non-clonal species.

Conclusions: Species of Chusquea in the Venezuelan Andes are a physiologically relatively homogeneous group across a broad elevation gradient. Population genetic diversity appears to be more related with their flowering pattern and habitat conditions than with their growth form.  相似文献   

9.
ABSTRACT

A new species of ghost shrimp, Neocallichirus pinheiroi, is described based on specimens collected in subtidal habitats of Saquaira beach, northeastern coast of Brazil. This new species resembles N. lemaitrei Manning, 1993, but differs from it primarily in having a third maxilliped propodus expanded ventrally, and in the case of males, a large subtriangular tooth on the cutting edge of the major cheliped dactylus. Diagnostic features of the new species include: (i) frontal margin of carapace with rounded lateral projections not exceeding rostrum distal margin, (ii) third maxilliped carpus with row of sclerotized setae on median internal surface, (iii) minor cheliped with cutting edge of dactylus microscopically pectinate, (iv) endopod of male second pleopod with appendices interna and masculina. This is the seventh described species of the genus Neocallichirus from the western Atlantic and the fourth report of this genus in Brazil. A key for identification of western Atlantic species belonging to the genus is provided.  相似文献   

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We describe a new species of the genus Notonecta, i.e. Notonecta mazzoniae n. sp. from the Lower Cretaceous of Argentina. It is the first fossil representative of the family described from South America, demonstrating the great antiquity of the genus, bearing identical ventral chaetal system correlated with respiratory for such a long period. The new species is recorded only by immature stages from the second to the fifth instars. Specimens are considered to be exuviae and not body fossils. Absence of body fossils may be due to taphonomic bias instead of palaeoecological constrains. In addition we found some specimens of Anisopinae, also considered as nymph exuviae, which represent the oldest record of the taxon.  相似文献   

13.
The current study focuses on four species from the primarily marine diatom genus Craspedostauros that were observed growing attached to numerous sea turtles and sea turtle‐associated barnacles from Croatia and South Africa. Three of the examined taxa, C. danayanus sp. nov., C. legouvelloanus sp. nov., and C. macewanii sp. nov., are described based on morphological and, whenever possible, molecular characteristics. The new taxa exhibit characters not previously observed in other members of the genus, such as the presence of more than two rows of cribrate areolae on the girdle bands, shallow perforated septa, and a complete reduction of the stauros. The fourth species, C. alatus, itself recently described from museum sea turtle specimens, is reported for the first time from loggerhead sea turtles rescued in Europe. A 3‐gene phylogenetic analysis including DNA sequence data for three sea turtle‐associated Craspedostauros species and other marine and epizoic diatom taxa indicated that Craspedostauros is monophyletic and sister to Achnanthes. This study, being based on a large number of samples and animal specimens analyzed and using different preservation and processing methods, provides new insights into the ecology and biogeography of the genus and sheds light on the level of intimacy and permanency in the host–epibiont interaction within the epizoic Craspedostauros species.  相似文献   

14.
Burmeistera, Centropogon, and Siphocampylus together comprise more than 500 species endemic to the Neotropics, Current knowledge of these genera is unsatisfactory, with much diversity yet to be described. Over the past seven years, one out of every 28 specimens received for identification has represented a new species, many characterized by unique or unusual character states. Siphocampylus smilax (Bolivia) is unique in the genus in its parallelodromous leaf venation and extra-floral nectaries. Centropogon dianae (Peru) cannot be accommodated in any recognized infrageneric taxon, and a new section, Centropogon sect. Niveopsis, is proposed for it. The flowers of C. steinii (Ecuador) are the smallest known in the genus, while C. connatilobatus (Venezuela) is the first species to combine arbusculiform pubescence and connate calyx lobes. Burmeistera venezuelensis is only the second species of the genus known to occur in Venezuela and the first to be endemic; similarly, Centropogon wilburii is only the third species of Centropogon known from Mexico and the first to be endemic to that country. Additional novelties are also described.  相似文献   

15.
Sixteen tardigrade species have been identified from a total of 943 specimens isolated from 69 positive soil samples collected in southern Spain (Andalusia, Huelva). Three genera (Hexapodibius, Xerobiotus and the new genus Sarascon) and eight species are new records for the Iberian Peninsula, increasing Iberian tardigrade biodiversity by 6%, and 10 species are new records for soil habitats, increasing soil tardigrade biodiversity by 9% (from 96 to 108 species). A newly discovered species and genus are described, followed by an analysis and discussion of the species' phylogenetic position and synapomorphies, based on morphological and total evidence (morphology and molecular – 18S and 28S rRNA – data combined) phylogenetic analyses. The new genus is distinguished from other Itaquasconinae genera, to which it is phylogenetically related, by having a Parascon buccopharyngeal apparatus and Ramajendas claws. In contrast to general eutardigrade evolution, which is primarily determined by claw morphology, itaquasconid evolution is more related to buccopharyngeal apparatus morphology, which shows homoplastic evolution at superfamily, family and subfamily levels, and also defines functional trophic groups in soil-related environments.

http://zoobank.org/urn:lsid:zoobank.org:pub:068B9D87-27E2-4B26-8920-FF03CEF9869A  相似文献   

16.

Plesiochorus Looss, 1901 is a genus of Gorgoderidae infecting the urinary bladders of marine turtles globally. Currently, just two morphologically similar species are recognised, Plesiochorus cymbiformis (Rudolphi, 1819) Looss, 1901 and Plesiochorus elongatus Pigulevsky, 1953, which have been distinguished by molecular data and subtle morphological differences. Here we describe a new species, Plesiochorus irwinorum n. sp., infecting hawksbill turtles (Eretmochelys imbricata (L.)), which is primarily distinguished from the other two species of Plesiochorus on the basis of ITS2, cox1 and 28S sequence data. Morphometric data for specimens examined during this study overlap between P. cymbiformis and P. irwinorum n. sp. for every measured feature, rendering them functionally cryptic. However, principal components analysis clearly distinguishes the two species. Additionally, we report new specimens of P. cymbiformis, and provide new sequence data for specimens from Australian loggerhead (Caretta caretta (L.)) and hawksbill turtles. There is little understanding of the host-specificity or geographical distribution of the three species of Plesiochorus, and it remains possible that some of the previously reported sequences have been attributed to the wrong species.

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17.
The genus Meira Jacquelin du Val 1852 is revised, four lectotypes and a neotype are designated, a new synonymy is proposed and four new species from France – one from Alpes-Maritimes (Meira alpina n. sp.), two from Var (M. echinoides n. sp. and M. teloniensis n. sp.), one from Vaucluse (M. germanni n. sp.) and one from Italy, from Abruzzo (M. osellai n. sp.) are described,. Synonyms, bibliographic and ecological data are provided. Whole-body photos of the types of the old species and of the four new species, drawings of systematically important characters, keys and distribution maps are also presented.  相似文献   

18.
Abstract

The cambial activity in Nerium oleander L. in Genoa. – The cambial activity in Nerium oleander L. is observed in order to compare the increasing rhythm of a specimen cultivated in Genoa with the rhythm of spontaneous and cultivated specimens growing in Puglia and Lucania, previously studied by other authors.

In Genoa Nerium oleander, a strongly scleromorphus species, has a nearly continuous growth activity, as already remarked at Policoro. However in Genoa a summer pause can be observed which is perhaps connected with the exceptional summer draught which occurred during the period of our research.

It can be said that the cambial activity, potentially continuous in Nerium, is modified by the environmental conditions.  相似文献   

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The catshark genus Holohalaelurus Fowler is currently represented by five species distributed off the southern and eastern parts of the African coast. Very few parasitological records exist for any of these five species, representing a significant knowledge gap. We report the first monogenean species from the bathydemersal species Holohalaelurus regani (Gilchrist): a new species of Microbothriidae Price, 1936, Leptomicrobothrium holohalaelure n. sp. from the dorsal skin surface, and a new species of Hexabothriidae Price, 1942 representing a new genus, Scyliorhinocotyle narvaezae n. gen., n. sp., from the gill lamellae. Both monogenean records represent the first for any member of the catshark genus Holohalaelurus. Previously we focused on the identification of monogenean taxa of emerging veterinary importance for public aquaria. We now begin a focused effort to document a generally unexplored monogenean biodiversity from diverse marine habitats off South Africa.

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